2018 ASHS Annual Conference

Fruit flavor is one of the most important trait for strawberry breeding. In our previous study, γ-decalactone regulated by FaFAD1 gene, contributes to fresh peach flavor and is associated with an increase in sweetness in fruit. The dominant FaFAD1 marker developed from the FaFAD1 gene is currently used for the high-throughput marker-assisted seedling selection (MASS) for γ-decalactone. However, the main limitation in using dominant marker is not possible to differentiate homozygosity and heterozygosity. Also because of the unique amplification of the target fragment, failures in polymerase chain reaction (PCR) or non-amplifications can be interpreted as an absence of the allele. Thus, an internal amplification control has to be carried out to determine the success of PCR. This is a bottleneck for high-throughput MASS with large breeding samples. . Therefore, in this study, codominant single-nucleotide polymorphism (SNP) markers for FaFAD1 were developed for the effectiveness of MASS. To identify SNPs associated with FaFAD1, the 100kb genomic region of FaFAD1 was sequenced with GD producing and nonproducing accessions: 10 producer (FL10-24, ‘Sweet Charlie’, ‘Albion’, FL11.28-34, Florida 127, ‘Winterstar’, FL12.115-10, ‘Elyana’, ‘Benicia’, and FL11.139-10) and five non-producer (‘Festival’, ‘Winter Dawn’, ‘Mara des Bois’, FL13.55.195, and FL12.74-39). Four unique SNPs that can differentiate GD producers and non-producers were identified and used to develop for high-resolution melting (HRM) markers. Two HRM markers GD2-001 and GD4-001 successfully detect the presence and absence of GD in all accessions tested. We further tested these markers with crude extract DNA to examine the accuracy of the high-throughput MASS. Both markers accurately detected γ-decalactone producing accessions The markers developed from the present study will be useful for strawberry breeding program for enhancing fruit quality.